A046898 Partial sums of A046897.

1, 4, 8, 11, 17, 29, 37, 40, 53, 71, 83, 95, 109, 133, 157, 160, 178, 217, 237, 255, 287, 323, 347, 359, 390, 432, 472, 496, 526, 598, 630, 633, 681, 735, 783, 822, 860, 920, 976, 994, 1036, 1132, 1176, 1212, 1290, 1362, 1410, 1422, 1479, 1572, 1644, 1686, 1740, 1860

Offset

1,2

Links

Table of n, a(n) for n=1..54.

Wikipedia, Jacobi four square theorem

Formula

G.f.: 1/(1 - q) * Sum_{k>=1} k * q^k / (1 + (-q)^k). - Seiichi Manyama, Jun 21 2024

Mathematica

Accumulate[DivisorSum[#1, # &, Mod[#, 4] != 0 &] & /@ Range[50]] (* Jayanta Basu, Jun 30 2013 *)

Prog

(PARI) my(N=60, q='q+O('q^N)); Vec(sum(k=1, N, k*q^k/(1+(-q)^k))/(1-q)) \\ Seiichi Manyama, Jun 21 2024

Crossrefs

Cf. A046897.

Sequence in context: A311074 A104655 A309192 * A311075 A311076 A171070

Adjacent sequences: A046895 A046896 A046897 * A046899 A046900 A046901

Keyword

nonn

Author

N. J. A. Sloane

Extensions

Offset changed from 0 to 1 by Seiichi Manyama, Jun 21 2024

Status

approved